Spark-plug and method of making the same.



C.A. MEZGER.

SPARK PLUG AND METHOD 0F MAKING THESAME.

APPLICATlON FILED JAN. 3l. 19|?.

4 SHEETS-SHEET l.

' C. A. NIEZGER.

SPARK PLUG A1110 METHOD 0F 111/1111111@ THE SAME.

APPLICATION FILED 1AN.3\.19IT.

Patented Dec. 8, 1918.

^ 4 SHEETS-s115121 2.

C. A. MEZGER.

SPARK PLUG AND METHOD or MAKING THE SAME.

APPLICATION FILED IAN. 3l` |911- v Patented. Dec..3, 1918.

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l SPARK-PLUG AND METHOD 0F MAKING THE SAME.

nasen Specication of Letters Patent.

Patented Dec. 3, lill Continuation of application Serial No. 395,67a, Ied-Qctober 3, 1907. This application tiled January 31, 1917.

' Serial No.

To all whom t may concern? i Be it known that l, CHARLES A. Muzeau, a citizen of the United States, and a resident of borough of Brooklyn; county of Kings', city and State of New York, have invented certain new and useful improvements in Spark-Plugs and Methods of Making the Same, of which the following is a descrip tion in such full, clear, and exact terms as will enable any person skilled in the art to which it pertains to make and use the saine.

My invention relates to the manufacture of spark plugs for internal combustion or explosive engines.

Heretofore the practice in this art has generally been to form the body of the plug by boring and turning it from a solid bar of hexagonal or other shaped 4metal involving losses both in labor and material. My invention seeks to save'` these losses and produce a better article` at less expense than that heretofore involved.

1 attain this end by'forming the body portion of the plug from metal by stamping, drawing, pressing.v or spinning the saine up into the requisite form, whereby l not only all save a great amount of metal but a corresponding saving in labor and time is edected.

My invention involves other features of importance all of which will be fully set forth hereinafter and particularly pointed out in the claims.

The accompanying drawings show the improved method of making the spark plug. as Well as various preferredv forms of the saine. and in these drawings- Figuresy 1 to 5 .how the successive operations of drawing up the body blank from a flat sheet of metal.

Figs. 6 to 12, 15 to 20, 26, and 29 to 35 are detailed views showing the various forms of spark plug bodies and other partsproduced by and in accordance 'with my invention, the details of which will be fully set forth hereinafter.

Figs. 13, 14, 21 to 25, 27, 28 and 36 illust-rate the tools employed in accordance with my invention land the process thereof as will also be fully set forth hereinafter.

. Referring to Figs. 1 to 5, L10 indicates the circular blank of sheet metal of which li form a cupped blank or a blank tube'from either of which l form the spark plug body in reference to cutting tube blanks. from lengths of tubing. This blank is drawn up into c upped form by any of the well-known methods of stamping, pressing, spinning or otherwise as indicated at 4:1 in Fig. 2.

number of different stages may have to be resorted to to prevent doing violence to the metal as will be understood by metal workers. 42, Fig. 3, shows another stage of the progressive cupping of the inetal and all Fig. 1l, shows what may be supposed to rep resent the final clipping operation. lt is un'- iniportant to iny invention how many stages are employed in this clipping operation. l` his will depend and the depth and forni of the cup of which the' spark plug body is made. 4l, in Fig. 5, represents a further stage in the drawing operation which may be resorted to if desired according to which the lower part of the cup is rolled in or compressed as the Vdrawing shows.

The closed end of the cup blank Fig.

et, may be cut or punched out., thus to forni a tubular blank instead of the end being rcinoved after subsequentl operations as described hereinafter.,A A

Figs. G and 7 illustrate the next step in the operation according to which the spark plug ody is Worked into shape, comprising a collar 45, at its upper end adapted to be internally threaded to receive a gland for holding the porcelain or other insulation in place as will be hereinafter described; a hexagonal portion i6 for the application of a wrench; a double bend 47 to receive and hold a collar 4:8; a cylindrical portion 49 to be externally threaded to screw into the engine cylinder; and finally, a reduced inner portion 50 which is subsequently punched or bored out on its lower part to allow the electrode to project centrally from the plug as will be fully understood and is illustratedl in figures of the drawings to be hereinafter described.

Referring to Fig. 8 it will be noted that the structure there shown resembles 'that shown inl Fig. G excepting 'that the reduced part 50 is tapered slightly and has a further construction 51 at its inner or'lower end. rll`he construction shown in Fig. 8 is further differentfrom that shown in Figs. 6 and "l" in that no provision is made for the appli cation of a ring or gasket such as the elcment 48 in Figs. Gand 'l'. Fig. il, a9 represents the part to be externally threaded, fitti represents the hexagonal portion, and 4.5

upon the character of the metal l. titl) tion and i represents the collar which is to be internally; threaded to receive the gland.

. noted that different thicknessesof metal are indicated in the's'ection Fig. 10 which differ- 'ent-thicknesses of bythe'turning'operation whereas upon reing of the hexagonal linto a hexagonal shape 52 said body through the die. sist-s shape 57. The

Fig. v6, f

metal in thel end 59 metal are best obtained vferring to Figs.4 6 and 8, for example, it will be seen that the metal thicknesses are formed at all points which indicates that the operation there is strictly a drawing operation from a plate of metal of uniform thickness. f

.After the blanklbody is formed as in Figs.

9 and 10 the part 52 must be transformedl as shown in Figs. 1.1 and 12 and a gasket ring 55 (dotted lines Figsfll and l2) may be applied.' The shapportion 52a, Fig. 12, from the round portion 52, Fig. 10, is preferably effected in a die such as shown in Figs. 13 and 14' and combined with a suitable plunger tool which is entered into the end 52 of the body shown in Fig. 10 and forces of a ring 56 with a. hexagonal inner blankv body shown in Fig. 0 is driven down through this die block,

onal form 521of Fig. 12. VReferring to Figs. l5. and 16 it will be noted that these illustrate a spark plug ody which is reversed with respect to that shown in some of the other figures, for example, Figs. 6 and 8. In Figs. 6 and 8 the hexagonal portion is on the open end of the i cup whereas 1n Figs. 15 and 16 the hexagouai portion 58 in Figs. -15 and` 16 is produced by a pure operation without any tool work exceptin that the closed upper end of the plug in icated at 59 in Figs. 15 and 16 vmust bepunched out or pierced and a flange similar to that 'designated 45 in 'or example, vturned up from the sov as toform an upstandinmcollar which may subsequently be internafl ring which holds in place the porcelain or turning or machine ing, spinning or drawing opera-V.

. This die con-A tion 6 5.

is formed on the closed end of the cup. This cui) at ravving or compressingy threaded to receive the gland or other insulation. Still referring to Figs. 15 and '16, after the closed end 59 of the body has been treated as described the lower part ofthe body may then beA pressed, drawn, rolled or otherwise reduced in diameter as indicated by the broke'nlines 60 in Fig. 16 thus-` giving .the necessary shape to the inner part of the plug body or shell as will be nderstood from the previously described ures.

gFig. 17 illustratesa form of stamped the same is made in two drawn or stamped parts 61 and 62 united by a welt or other seam 63. Sometime it may be advantageous body in. two drawn sections rather than in one as previously described herein and Fig. 17 is to illustrate this two-part formation. It will be noted that the essential elements of the spark plug body as heretofore described are preserved the drawn,

the structure shown in Fig. 17y 1I. e. 61

ermits the e from the .this gland is shown in Figs. 18, 1.9 and 20.

Referring to these figures 6.4 cylindrical ortion of the gland which is intended to be exteinall threaded to screw into theopen outer endy is placed under the enlarged hexagonal por- Preferably the gland illustrated in Figs. 18 and 19 is formed of stamped or drawn sheet metal in the same manner described in connection with the' spark plug bodies heretofore described in Figs. 6 and 8 and 15 and 16 for example. This gland would be formed by stampin so that a cup is first produced and then ghe closed end of the cup is' compressed suitable die f the cup in Fig. 19 is then punched open as indicated by the broken lines 6 7 in said view producing the opening through the gland through which the vinsulation projects.

Going back to Figs. 5 and 6 before described, and referring to Figs. 21 to 23 in connection therewith, Figs. 2l to 23 illustrate a metal ed to take a blank tube or the blank cup such as shown in Fig. 4 andt-transformthe or spun spark plug body in which the cylinder of the engine and drawlng` or pressing tool adapti vsame inte the body shape shown in Fig. 6. V

- annessa These Figs. 21 to 23 also illustrate particuframe or table in which a die block 69 is placed', the same havin a cavity of 3 diameters indicated -at 70, 7 and 72 in Figs. 21

and 23.; On the table 68 is a waterlpan 73 which has an opening in its bottom so that the water therein may enter and fill the cavities of the die 69: Comparing with thel die block 69 is a die block 74 of which Fig.

22 is a inverted plan `or end view. Thisdle block has a hexagonal cavity 75 in its open lower end above which is a reduced circular cavity 76. 78 are water relief passages placed at various points to permit the eirpansion of the water as will appear hereinafter.` An ejector 79 operates in the bottom of the die 69and a press lunger` 80 operates over. the die. This p unger has a stem 81 on the lower end of which the die section 74 is loosely carried. 82 is a .spring which presses the section 74 down on the lower end of the stem 81. Within the stem 81, is a relief plu 83 pressed down by a spring 84 seated in a cavity in the plunger81.

The operation of the device shown in `Figs. 21. to 23 is as follows: The cup metal r blank body such for example, has a cup 43 shown in Fig. 4, is placed in the lower die 69 in the position shown in Fig'. 21 on top of' the ejector 79. The pan 73 and the die 69 will have been previously filled with wateror any other non-compressible liquid.

This water fills the die 69 and fills thev inn j terior of the blank 43 and lies in the pan 73 l over the top of the blank as shown. The

blank is then inserted into the lower die section 69 when Vthe press plunger 80r is raised and the die section 74 stands up above the surface of the water and indeed above the top edge of the pan 73. The press plunger 80 now descends and when the parts rnoted that the lower part 'of the die section 74 is submerged in the water, the water completely fills the blank 43 and also fills the interior of the die section 43. The relief plunger 83 enters'the open upper end of the body section. The press' plunger does not pause, however, at this point but continues 'ts downward movement, the springr 82 yielding to allow the plunger stem 81 to move down in the die section 74 which die section can at this time move no farther owing to the fact that it has fetched up lon top vof the die 69. The result of this con tinued downward movement of theplunger stem is important. The water, within the blank 43 is trapped therein and cannot escape (the open upperend of the blank having been previously joined with the lower end ofthe plunger stem 81), the water in reach the position shown in Fig. 21 it will be the die section'74 outside of the blank `and in the die section 69 outside of the blank` I 43 is free, however, to be discharged through l th`e various relief openings 78. ln the continued downward movement of the plunger stem 81 pressing on the spark plug body 43 and the Water trapped within the body making it impossible for the body to collapse unthe die sections 69 and 74 and the body will take the form ofthe interior walls of said cavities. Comparinglig. 6 with Fig. 21 it will be noted that the part 50 of the blank in Fig.,6 is shaped by the upper part of the cavity 72, the part 49 is shaped by the enlarged cavity 71, the hexagonal portion 46 is shaped and formed by the cavity 7 5 of the die section 74 which cavity is hexagonal in form as indicated by the broken lines in Tfig. 2l, and the upstanding collar 45 is formed v`by the lower part of the cavity 76 in the die section 74. 48 in Fig. 2l indicates the `packing ring shown in Fig. 6 which packing ring 48 is placed" loosely in the cavity 70 of the die section 69 before thel die section 74 descends to the position shown in Fig. 21. Then the crushing strain which the plunger arm exerts on top of the 'body blank 43 combined with the forms of the cavities in the die blocks as before described and with the action of the water within said blank which makes it impossible forthe -blank to collapse, causes the metal plate of which the blank if formed to bend itself around the gasket 48. The metal of the blank thusbends around the inner edge of the gasket because the resistance to this bending is less than the resistance to the disf ruption of the ring 48. This is true since the ring 48 is firmly held and pressed in the cavity 70 of the die section 69 and the strain is edge-wise on the ring whereas the bending strain on the body section is sidewise to the metal thickness and the body section is therefore forced to give and fold 'itself around the ring. The relief plunger 83 is provided simply 't0 account for any change in the interior volume of the blank 43 and its changes from the shape shown in Fig. 6 to that shown in Fig. 16. The water int-the blank cannot escape and itis a purpose of ingl out with `the body being indeed an iii of the die devices shown 'in Figs. 21 and 6I sepai'a'blepart. thereof owing to the opera- 24 I may form this upstanding flange by tions before. described. rolling the same against' the mandrel as in- Figs. 24 to 28 will, it is thought, be easily dicated in Fig. 36 where 97 indicates the roll understood from the foregoing description and 98 the mandrel, the latter entering the of Figs. -21 to 23. Fig. 26 illustrates the open end of the body blank which is. indi- -70 finished spark plug' 4 body resulting from cated at 99 in Fig. 36. The roll 97 swages the operation of the die shown in Figs. 24, or rolls in the body' and forms the reduced 25 and 27 and-28, excepting. of course, that upstanding collar. The particular device io the threads on the spark plug body must be' shown in Fig.Y 36 contemplates vsubsequently performed in the usual threading machine. cutting off the surplus end 100 after the roll- 75 In Fig. 26 85 indicates an upstanding flange ing operation shown in this figure has been which is internally threaded to receive the performed.

gland such for instance as-that shown in In view of the aforegoin description it v Fig. 19, 86 indicates'the hexagonal portion .is thought that the assemb ed spark plug 87, a cylindrical portion below the hexand views in Figs. 29, 30 and 31 will be easily 80 88 the threaded inner part of the body which understood.

, screws into the cylinder head. Fig. 29 shows the plug assembled from the Still referring to Figs. 24, 25,27 and 28, body blank illustrated in Figs.9 to 12. The

a cupped ortube blank such as blank 44 'part 53 of the blank has been threaded exin Fig. 5 is inserted into the die 89. In the ternally and the part 52a threaded inter- 85 figures now being described there is but nally. The tapered part 53 has been opened one die section which has a cavity of various at its end to let the central electrode 101 diameters terminating in the hexagonal porprotrude. 102 represents the usual procelain tion 90 at the top of the die. 91 is the water with the enlargement 103 engaging gaskets pan. similar to Athat before described in con- 104 which are kept in place by the gland 90 nection with Fig. 21. 92 is the press plunger 64-65 formed preferably as shown in Figs.

` which has a stem 93, the lower end of which 18 and 19 with or without the gasket 66 of ls raised as indicated at 94 to embrace the Fig. 20.

upper end of the blank 43; This raised end y Fig.`30 shows the adaptation of the body of the plunger stem confines the upper end of Fig. 8 to the assembled spark lug and it 05 of the blank and as the plunger stem conis believed that the bodyy porcelain and continues to descend from the position shown ductors or electrodes will be obvious from in Fig. 25 to the position shown in Fig. 26 the drawing. The gland 105 in Fi 30 is 85 the upper extremity of the blank 44 is conpreferably formed as in Fig. 19 be ore defined by the raised plunger steinand the scribed with the gasket 66 o Figs. 18 to 20. 100 lower cavities of the die 89 confine and hold The inner end of the gasket 105 is rolled in the shape of the lower part of the body 44. around the enlargement of the porcelain to he crushing of the A O dy Consequently confine a packing gasket 106 and the upper leaves but One movement 0f the metal pOS- end carries a tapering gasket 107 preferably sible and that is expansion of the upper po'rof metal which is fastened in the gland as 108 tion of the blank outward into the hexagonal shown. The gland therefore with the parts 'cavity 90 of the die 89 and gives the blank: 106 and 107 and with or without the art 66v the form shownvin Fig. 25 which represents is permanently united to the porce ain of the extra downward movement of the press the spark plug and may be removed only plunger stem .93.- The stem is then withwiththe porcelain. 110 drawn and the body is thrown out by the Fig. 31 shows the spark plug body also of ejector 95. Fig. 27 is a planrview of the die the general form illustrated in Fig. 6 but 8 9 and shows the hexagonal cavity90 in here the porcelain is permanently united the upper part thereof which conforms ex-l with the body of the spark plug and there is actly to the cross-sectional shape of the stem no' gland such as the element 64 of Figs. 19 115 93 as indicated at 94 and Fig. 28 is a bottom. and 29 or 105 of Fig. 30. This permanent end view of the stem 93 showing the cavity union is effected' by shouldering the porce- 94 which receives the upper end of the body lain against the gasket 108 on the lower side blank as before described. When the body of the porcelain enlargement and a taperblankv is thrown out of thedie after having ing Ametal ring gasket 109 on the upper side. 120

been shaped as shown in Fig. 2.5 the closed After-theseparts are inserted the upstandend thereof is opened-by cutting it away ing flange or neck 45 of the body formed as with ,a suitable tool as indicated at 96 in in Fig. 6 is rolled or crimped inward around A Fig'. 26 and the collar 85 is internally the-gasket 109 thus permanently fastening v threaded and the part 88 exteil'pally threaded the porcelaininthe ody so that it cannot 126 thus finishing the `body blan be removed, as well4 as clenching or clamp- Instead of forming the 'upsta-nding flange ing the packing .108 and 109 against the 45 or 4.5a (Figs and 7) by the action porcelain and disposing altogether of the lll y29. and 30.

and sectional views of thegasketsl09 and the body,

stronger body with a f'naeaaea use of a gland such as is employed in Figs. Figs. 32, 33, 34 andv 35 are plan 108, the form being a soft metal ring tapered in section and the latter an annular sheet metal casingr inclosing an asbestos thread weight of material, and at a consequent low cost.

This application is a continuation of my (1o-pending application tiled Uctober 3rd, i907, Serial No., 395,678.

lBy the term drawn or used in the claims, t u methods of shaping by bending, pressing, or de-shaping, through the various mechanical for the purpose such as drawing, as

agencies known @additional drawing, pressing,I

lL 1 intend to cover allv metal stamps, presses, spinning rolls, and the like. i

i The term metalblanlrs as used in the claims is Aintended in its broad interpretation.

to cover dat metal blanks, metal cups, metal tubes, ory any form or metal blank requiring spinning, or

rolling operation to shape it into the formiof a spark plug body.

1What ll claim is `l. rllhe method of making; a spark plug: body having a cylindrical portion adapted to be eirteriorly threaded and an angular tool engaging portion, which consists `in iirst drawing a metal blank into hollow Jform and.

subsequently submitting it to a die-shaping operation for making the angular tool enraging portion,

2. A spark plug: body consisting of a drawn metal sleeve havinga cylindrical portion adapted to be enteriorly threaded and an angular tool engaging; portion.

ln testimony whereof ll have hereunto signedy my name in the presence of two witnesses,

Cllillla@ A'. MEEGER.,

"Witnesses:

Parisien; A. Bonomi,

llsanc B. Owens. 

